mydata = read.table("measurements", header=TRUE, sep=",")

#second degree
fit2 <- lm(y~poly(x,2,raw=TRUE), data=mydata)

xx <- seq(min(mydata["x"]), max(mydata["x"]), length=100)
plot(mydata)
lines(xx, predict(fit2, data.frame(x=xx)), col="green")